Apparatus for gripping a tubular on a drilling rig

ABSTRACT

Methods and apparatus are provided for running tubulars into and out of a wellbore. A tubular handling system having a tubular gripping apparatus having a gripping mechanism and a sensor adapted to track movement of the gripping mechanism, wherein the sensor sends a signal to a controller when the gripping apparatus is in a position that corresponds to the gripping apparatus being engaged with the tubular

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/009,475, filed on Jan. 19, 2011; which is a divisional of U.S. patentapplication Ser. No. 11/609,709, filed on Dec. 12, 2006, now U.S. Pat.No. 7,874,352; which application claims benefit of U.S. ProvisionalPatent Application Ser. No. 60/749,451, filed Dec. 12, 2005. Each ofabove referenced applications is incorporated herein by reference in itsentirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention generally relate to a grippingassembly for gripping tubulars. More particularly, the invention relatesto a gripping apparatus for connecting wellbore tubulars on a drillingrig. More particularly still, the invention relates to a method ofoperating a tubular handling system.

2. Description of the Related Art

In the construction and completion of oil and gas wells, a drilling rigis located on the earth's surface to facilitate the insertion andremoval of tubular strings to and from a wellbore. The tubular stringsare constructed and run into the hole by lowering a string into awellbore until only the upper end of the top tubular extends from thewellbore (or above the rig floor). A gripping device, such as a set ofslips or a spider at the surface of the wellbore, or on the rig floor,holds the tubular in place with bowl-shaped slips while the next tubularto be connected is lifted over the wellbore center. Typically, the nexttubular has a lower end with a pin end, male threaded connection, forthreadedly connecting to a box end, female threaded connection, of thetubular string extending from the wellbore. The tubular to be added isthen rotated, using a top drive, relative to the string until a joint ofa certain torque is made between the tubulars.

A tubular connection may be made near the floor of the drilling rigusing a power tong. Alternatively, a top drive facilitates connection oftubulars by rotating the tubular from its upper end. The top drive istypically connected to the tubular by using a tubular gripping tool thatgrips the tubular. With the tubular coupled to a top drive, the topdrive may be used to make up or break out tubular connections, lower astring into the wellbore, or even drill with the string when the stringincludes an earth removal member at its lower end.

An internal gripping device or spear may grip the inside diameter of atubular to temporarily hold the tubular while building a string orrotating the string to drill. An internal gripping device is typicallyconnected at an upper end to a top drive and at a lower end the internalgripping device includes outwardly extending gripping members configuredto contact and hold the interior of the tubular in order to transmitaxial and torsional loads. To engage the tubular, it may be useful tomonitor the position of the tubular gripping apparatus and the grippingmechanism in the tubular gripping apparatus.

There is a need for an improved tubular handling assembly capable oftracking a position of the tubular gripping apparatus and the grippingmechanism. There is also a need for an integrated safety system betweenthe gripping apparatus and a gripper on the rig floor.

SUMMARY OF THE INVENTION

Embodiments described herein relate to a method and apparatus forhandling tubular on a drilling rig. The apparatus is adapted forgripping a tubular and may be used with a top drive. The apparatusincludes a connection at one end for rotationally fixing the apparatusto the top drive and gripping members at a second end for gripping thetubular. The apparatus has a primary actuator configured to move andhold the gripping members in contact with the tubular and a backupassembly to maintain the gripping member in contact with the tubular.

In another embodiment described herein, a safety system for use with atubular handling system is described. The safety system includes asensor adapted to track movement of a slip ring for actuating a grippingapparatus, wherein the sensor sends a signal to a controller when thegripping apparatus is in a position that corresponds to the grippingapparatus being engaged with the tubular.

In yet another embodiment, the sensor comprises a trigger which isactuated by a wheel coupled to an arm, wherein the wheel moves along atrack coupled to an actuator as the actuator moves the slip ring.Additionally, the track may have one or more upsets configured to movethe wheel radially and actuate the trigger as the wheel travels.

In yet another embodiment described herein, a method for monitoring atubular handling system is described. The method includes moving agripping apparatus toward a tubular and engaging a sensor located on astop collar of the gripping apparatus to an upper end of the tubular.The method further includes sending a signal from the sensor to acontroller indicating that the tubular is in an engaged position andstopping movement of the gripping apparatus relative to the tubular inresponse to the signal. Additionally, the method may include grippingthe tubular with the gripping apparatus.

In yet another embodiment, the method further includes monitoring aposition of one or more engagement members of the gripping apparatusrelative to the tubular using a second sensor, and sending a secondsignal to the controller indicating that the gripping apparatus isengaged with the tubular.

In yet another embodiment, the method further includes coupling thetubular to a tubular string held by a spider on the rig floor andverifying that the tubular connection is secure.

In yet another embodiment, the method further includes having verifiedthe tubular connection is secure and the gripping apparatus is securethe controller permits release of the spider.

In yet another embodiment, a method of handling a tubular includesgripping the tubular with a gripping apparatus; sending an electronicsignal to a controller indicating that the gripping apparatus isgripping the tubular; and controlling actuation of the grippingapparatus using the controller to prevent inadvertent release of thetubular.

In yet another embodiment, a tubular handling system includes a grippingapparatus; and a controller operable to receive an electronic signalindicating a position of the gripping apparatus, wherein the controlleris operable to control actuation of the gripping apparatus to preventinadvertent release of a tubular supported by the gripping apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention may be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 is a schematic of a drilling rig and a wellbore according to oneembodiment described herein.

FIG. 2 is a schematic of a gripping member according to one embodimentdescribed herein.

FIG. 3 is a schematic of a gripping member according to one embodimentdescribed herein.

FIG. 4 is a schematic of an actuator for a gripping member according toone embodiment described herein.

FIG. 5 is a schematic of a hydraulic actuator according to oneembodiment described herein.

FIGS. 6A-6C show a schematic of a gripping member according to oneembodiment described herein.

FIG. 6D shows a cross sectional view of a swivel according to analternative embodiment.

FIG. 7 is a schematic of a hydraulic actuator according to oneembodiment described herein.

FIG. 8A is a schematic of a hydraulic actuator according to oneembodiment described herein.

FIGS. 8B-8E show a schematic of multiple gripping members according toone embodiment described herein.

FIGS. 9A-9B show a schematic of a location system according to oneembodiment described herein.

FIGS. 10A-10B show a schematic of a sensor according to one embodimentdescribed herein.

FIGS. 11, 11A-11C show a schematic of an adapter according to oneembodiment described herein.

FIGS. 12A-12B show a schematic of a cement plug launcher according toone embodiment described herein.

FIG. 13 is a schematic view of a release mechanism according to oneembodiment described herein.

FIG. 14 is a schematic view of a tubular handling system and acontroller according to one embodiment described herein.

DETAILED DESCRIPTION

FIG. 1 is a schematic view of a drilling rig 100 having a tubularhandling system 102. As shown, the tubular handling system 102 includesa gripping apparatus 104, an actuator 106, a drive mechanism 108, and ahoisting system 110. The tubular handling system 102 is adapted to gripa tubular 112 or a piece of equipment 114 and lift it over the wellbore115 and then complete a tubular running operation. The actuator 106 forthe gripping apparatus 104 may be equipped with a backup safetyassembly, a locking system and a safety system, described in more detailbelow, for ensuring the tubular 112 is not released prematurely. Thehoisting system 110 and/or the drive mechanism 108 may lower the tubular112 until the tubular 112 contacts a tubular string 116. The drivemechanism 108 may then be used to rotate the tubular 112 or the piece ofequipment 114 depending on the application in order to couple thetubular 112 to the tubular string 116, thereby extending the length ofthe tubular string 116. After the coupling, a gripper 119 on the rigfloor 118, which initially retains the tubular string 116, may thenrelease the tubular string 116. The gripper 119 as shown is a set ofslips; however, it should be appreciated that the gripper 119 may be anygripper on the rig floor 118 including, but not limited to, a spider.With the gripping apparatus 104 gripping the tubular 112 and thereby thetubular string 116, the hoisting system 110, and/or drive mechanism 108may lower the tubular 112 and the tubular string 116 until the top ofthe tubular 112 is near the rig floor 118. The gripper 119 is thenre-activated to grip the extended tubular string 116 near the rig floor118, thereby retaining the extended tubular string 116 in the well. Theactuator 106 releases the gripping apparatus 104 from the tubular 112.The tubular handling system 102 may then be used to grip the nexttubular 112 to be added to the tubular string 116. This process isrepeated until the operation is complete. While lowering the tubularstring 116, the drive mechanism 108 may rotate the tubular string 116.If the tubular string 116 is equipped with a drilling tool 120, shownschematically, rotation of the tubular string 116 may drill out thewellbore as the tubular string 116 is lowered. The tubular 112 may beany jointed tubular or segment including but not limited to casing,liner, production tubing, drill pipe.

FIG. 2 shows a schematic view of the tubular handling system 102according to one embodiment. The tubular handling system 102 includes aswivel 200, a pack off 202, in addition to the drive mechanism 108, theactuator 106, and the gripping apparatus 104.

The gripping apparatus 104, as shown in FIG. 2, is an internal grippingdevice adapted to engage the interior of the tubular 112. The grippingapparatus 104 includes a set of slips 208, a wedge lock 210, and amandrel 212 coupled to the actuator 106. The slips 208 may be any slipor gripping member adapted to grip the tubular 112, preferably the slips208 have wickers (not shown) in order to provide gripping engagement.The wedge lock 210 is coupled to mandrel 212, which may be coupled tothe actuator 106. The actuator 106 moves a sleeve 214, or cage, down inorder to move the slips 208 down. As the slips 208 move down, the angleof the slips 208 and the angle of the wedge lock 210 moves the slips 208radially away from a longitudinal axis of the gripping apparatus 104.This outward radial movement moves the slips 208 into engagement withthe tubular 112. With the slips 208 engaged with the tubular 112, theweight of the tubular 112 will increase the gripping force applied bythe slips 208 due to the angles of the wedge lock 210 and the slips 208.Although FIG. 2 shows the sleeve 214 moving down in order to actuate theslips 208, any suitable configuration may be used in order to engage theslips 208 with the tubular 112. In another embodiment, the slips 208actuate by moving the wedge lock 210 up relative to the slips 208, thusforcing the slips 208 to move radially outward.

In an alternative embodiment, the gripping apparatus 104 may be anexternal gripper for gripping the exterior of the tubular 112. Theexternal gripper may incorporate slips which move toward thelongitudinal axis when actuated. Further, a combination of an internaland external gripping apparatus 104 may be used. Further still, theexternal gripper may incorporate gripping members which pivot in orderto engage the tubular. An exemplary external gripper is show in U.S.Patent Application Publication No. 2005/0257933, which is hereinincorporated by reference in its entirety.

The actuator 106 is shown schematically in FIGS. 1 and 2 and may be anelectrical, mechanical, or fluid powered assembly designed to disconnectand to set the gripping apparatus 104. Further, the actuator 106 may beany combination of electrical, mechanical, or fluid powered actuators.

The swivel 200 allows an electrical or fluid source such as a pump (notshown) to transmit a fluid and/or electric current to the actuator 106during operation, especially during rotation of the actuator 106. Theswivel 200 may be a conventional swivel such as a SCOTT ROTARY SEAL™with conventional o-ring type seals. The swivel 200, in FIGS. 2 and 3 ispart of a sub 215, which has a lower pin end 216 and an upper box end217 for coupling the swivel 200 to other rig components such as a topdrive or the mandrel 212. The upper end of the mandrel 212 may have anadapter 218, optional, for connecting the gripping apparatus 104 to theswivel 200 or the drive mechanism 108. The adapter 218 may simply be athreaded connection as shown or incorporate a locking feature which willbe described in more detail below. The drive mechanism 108 may be anydrive mechanism known in the art for supporting the tubular 112 such asa top drive, a compensator, or a combined top drive compensator, or atraveling block. The connection between the drive mechanism 108 and thegripping apparatus 104 may be similar to the adapter 218 and will bediscussed in more detail below. The mandrel 212 is configured such thatthe top drive will transfer a rotational motion to the slips 208, asdiscussed in more detail below.

The actuator 106 may be coupled to the mandrel 212 and operativelycoupled to the swivel 200. The swivel 200 may generally be a hollow orsolid shaft with grooves or contact rings and an outer ring having fluidports or brushes. The shaft is free to rotate while the ring isstationary. Thus, the fluid is distributed from a stationary point to arotating shaft where, in turn the fluid is further distributed tovarious components to operate the equipment rotating with the mandrel212, such as the actuator 106 to set and release the slips 208.

In one embodiment, the actuator 106 is two or more annular pistonassemblies 300, as shown in FIG. 3. Each annular piston assembly 300 mayinclude a piston 302, a fluid actuation chamber 304, a control line(s)308 (shown schematically), and a fluid inlet 310. Each annular pistonassembly 300 is capable of actuating the gripping apparatus 104independently of the other piston assemblies 300. Thus, there is a builtin redundancy to provide a back up safety system. That is, one of theannular piston assemblies 300 is a primary assembly which is necessaryto operation of the actuator 106. The remaining annular pistonassemblies 300 are redundant and provide an additional backup safetyfeature. Each annular piston assembly 300 operates by introducing fluidinto the fluid actuation chamber 304. The fluid in the actuation chamber304 applies pressure to the upper side of the piston 302. The pressureon the piston 302 moves the piston 302 down. The piston 302 isoperatively coupled to the gripping apparatus 104 via the sleeve 214.Although shown as coupled to the sleeve 214, it should be appreciatedthat any form of actuating the gripping apparatus 104 with the pistons302 is contemplated. In order to release the gripping apparatus 104 fromthe tubular 112, fluid may be introduced into a release chamber 306.When the fluid pressure in the release chamber 306 acting on the lowerside of the piston 302 is greater than the fluid pressure above thepiston 302, the piston 302 may move up thereby releasing the grippingapparatus 104 from the tubular 112. Each of the annular pistonassemblies 300 may have the release chamber 306 or none may be equippedwith the release chamber. It is contemplated that in order to releasethe gripping apparatus 104 the pressure in the actuation chambers 304 issimply relieved, the drive mechanism 108 may then be used to release theslips 208, shown in FIG. 2 from the tubular 112. Although shown ashaving two annular piston assemblies 300, it should be appreciated thatany number may be used so long as there is at least one primary pistonassembly and one redundant or backup piston assembly.

The control lines 308, shown schematically in FIG. 3, may be one controlline or a series/plurality of control lines for supplying fluid to eachindividual annular piston assembly 300. The control lines 308 mayinclude a monitor line to transmit information back to a controller 312.The control lines 308 allow an operator or the controller 312 to monitorthe conditions in the fluid chambers in each individual annular pistonassembly 300, including but not limited to pressure and temperature.Thus, if there is a sudden loss of pressure in one of the annular pistonassemblies 300, the controller 312 or the operator may make adjustmentsto the other annular piston assemblies 300 to ensure that engagementwith the tubular 112 is not lost. The control lines 308, although shownas a control line, may be any fluid source known in the art such as anannulus surrounding the actuator 106.

Generally, the controller 312 may have additional control linesoperatively communicating with a traveling block, a location system, asensor, the drive mechanism, a power tong, and/or a pipe handlingapparatus. Further, the controller 312 receives data from the monitorlines and the drive mechanism. The controller 312 in various embodimentsmay be in fluid, wireless (e.g., infrared, RF, Bluetooth, etc.), orwired communication with components of the present invention.Illustratively, the controller 312 may be communicatively coupled to thedrive mechanism, fluid chambers, gripping apparatus 104, a release, alocation system, one or more sensors, and other drilling rig components.The controller 312 may generally be configured to operate and monitoreach of the respective components in an automated fashion (e.g.,according to a preprogrammed sequence stored in memory) or according toexplicit user input.

Although not shown, the controller 312 may be equipped with aprogrammable central processing unit, a memory, a mass storage device,and well-known support circuits such as power supplies, clocks, cache,input/output circuits and the like. Once enabled, an operator maycontrol the operation of the gripping apparatus 104 by inputtingcommands into the controller 312. To this end, another embodiment of thecontroller 312 includes a control panel, not shown. The control panelmay include a key pad, switches, knobs, a touch pad, etc.

With the controller 312 monitoring and operating the drilling rig, anintegrated safety system may easily be adapted to the drilling rig 100.A safety system may prevent dropping a tubular 112 or tubular string116. In one embodiment, the safety system is adapted to provide anindication of whether the gripping apparatus 104 is properly connectedto the tubular 112. Thus, the safety system would allow an operator orthe controller 312 to know that the gripping apparatus 104 has fullyengaged the tubular 112. When engagement of the gripping apparatus 104to the tubular 112, which is now a part of the tubular string 116, isconfirmed by the safety system, the controller 312 or operator mayrelease the slips or spider at the rig floor 118. The traveling blockwould then lower the tubular string 116 so that the box end of thetubular is located near the rig floor 118. The controller 312 oroperator may then re-activate the slips or spider to grip the tubularstring 116. With the slips engaging the tubular string 116, thecontroller 312 would allow the gripping apparatus 104 to release thetubular string 116. The safety system is also capable of monitoring theproper amount of torque in the threads of the tubulars 112 during makeup. This ensures that the threads are not damaged during make up andthat the connection is secure. Examples of suitable safety systems areillustrated in U.S. Pat. No. 6,742,596 and U.S. Patent ApplicationPublication Nos. U.S. 2005/0096846, 2004/0173358, and 2004/0144547,which are herein incorporated by reference in their entirety.

In an alternative embodiment, the actuator 106 of the gripping apparatus104 includes one or more piston and cylinder assemblies 400, as shown inFIG. 4. The piston and cylinder assemblies 400 couple to the mandrel 212via a collar 402, and are moveably coupled to the sleeve 214 via a slipring 404. The slip ring 404 couples to a rod 406 of each of the pistonand cylinder assemblies 400. The slip ring 404 is operatively coupled tothe sleeve 214 in order to actuate the gripping apparatus 104. It shouldbe appreciated that any method known in the art of fixing the piston andcylinder assemblies 400 to the mandrel 212 and the sleeve 214 may beused. Any one of the piston and cylinders assemblies 400 are capable ofmoving the slip ring 404 in order to actuate the gripping apparatus 104,therefore, all but one of the piston and cylinder assemblies 400 isredundant or provide a backup, and one of the pistons is the primaryactuator. It should further be appreciated that other power sourcesbesides fluid sources may also be employed to power the grippingapparatus 104 either separately or in conjunction with the fluid power.These alternative power sources include, but are not limited to,electric, battery, and stored energy systems such as power springs andcompressed gas.

In another embodiment, the actuator 106 may be electrically powered. Theelectrically powered actuator may be equipped with a mechanical lockingdevice, which acts as a backup assembly, which prevents release of thegripping apparatus 104. Further, the electrically powered actuator mayinclude more than one actuation member for redundancy or as a backup.Further still, the electrically powered actuator may send data to acontroller 312 to communicate its position to an operator. Thus, if onelock fails, the controller 312 may take steps to prevent the accidentalrelease of the tubular 112.

As described above, in order to provide for redundancy or a backupsafety assembly, a separately operable redundant actuator may be used toensure operation of the gripping apparatus 104 in the event of failureof the primary actuator. In one embodiment, as shown in FIG. 3, theactuator 106 includes four annular piston assemblies 300. The primaryactuator may be one of the annular piston assemblies 300, while anyoneor all of the remaining annular piston assemblies 300 may act as theredundant actuator. The redundant actuator acts in the same manner asthe primary actuator. That is, the redundant actuator applies anactuation force to the gripping apparatus 104 when fluid is supplied tothe actuation chamber 304 of the redundant actuator. As discussed above,the fluid pressure in the actuation chamber 304 may be monitored by thecontroller 312. The redundant actuator will provide the actuation forceupon the gripping apparatus 104 even in the event of a primary actuatorfailure. Further, additional redundant actuators may be provided whichare operated in the same or a similar manner as the redundant actuator.

In another embodiment, one or more valves 314, shown schematically inFIG. 3, are disposed between the control line(s) 308 and the actuationchamber 304 to provide the additional and/or alternative backup safetyassembly. The valve 314 allows fluid to enter the actuation chamber 304,but does not allow fluid to exit the actuation chamber 304. The valves314 may be set to release the pressure when the release chambers 306 areactuated. The valve 314 is typically a one way valve such as a checkvalve; however, it should be appreciated that any valve may be usedincluding, but not limited to, a counter balance valve. In operation,the fluid enters the actuation chamber 304 and actuates the annularpiston assembly 300 thereby engaging the tubular 112 with the slips 208of the gripping apparatus 104. The fluid also acts redundantly toprevent the slips 208 of the gripping apparatus 104 from disengagingwith the tubular 112 until pressure is applied on the opposite end ofthe piston 302. In this embodiment, the valve 314 acts to maintain asubstantially constant pressure on the piston 302, even if fluidpressure is inadvertently lost in the control line(s) 308 or selectivelyturned off. This in turn keeps a constant locking force on the slips208. The valves 314 may be built into the actuator 106 or added and/orplumbed in as an add-on to the actuator 106. Further, the valve 314 maybe located anywhere between the fluid source for operating the annularpiston assembly 300 and the actuation chamber 304. The valve 314 may beattached to each actuation chamber 304 or any number of fluid chambersdepending on the requirements of the actuator 106. Thus, in operationonly one of the actuation chamber 304 is necessary to engage the slips208. The additional actuation chambers 304 may be equipped with thevalve 314 as a safety chamber that once actuated prevents the grippingapparatus 104 from accidentally releasing the tubular 112. The valves314 will work on a single piston basis. Thus, if multiple pistons areused and if one piston is lost or leaks off pressure due to a failedseal, the redundant actuator will continue to hold the setting force onthe slips 208.

In yet another alternative embodiment, the redundant actuator is one ormore of the piston and cylinder assemblies 400, and the primary actuatoris one of the piston and cylinder assemblies 400, as shown in FIG. 4. Asdescribed above, the primary actuator and each of the redundantactuators are capable of independently operating the gripping apparatus104. Further, the controller 312, shown in FIG. 3, is capable ofmonitoring conditions in the primary actuator and the redundantactuators in order to ensure that gripping apparatus 104 remains engagedwith the tubular 112 when desired.

In yet another embodiment, at least some of the piston and cylinderassemblies 400 are equipped with a valve 500, shown schematically inFIG. 5, in order to provide the backup assembly as an additional safetyfeature to prevent inadvertent release of the gripping apparatus 104. Asshown, each of the piston and cylinder assemblies 400 includes acylinder 502 and a piston 504. There may be two fluid control linesconnected to each of the piston and cylinder assemblies 400. Anactuation line 506 connects to each cylinder 502. The actuation line 506applies hydraulic or pneumatic pressure to each piston 504 in order toactuate the gripping apparatus 104 (shown in FIGS. 1-4). A release line512 connects to each of the cylinders 502 below the piston 504 in orderto release the gripping apparatus 104. A one or more feed lines 508 maycouple to each of the actuation lines 506. Further, separate feed linesmay be used in order to power each of the piston and cylinder assemblies400 separately. Each of the actuation lines 506 may be equipped with thevalve 500, although shown as each of the actuation lines 506 having thevalve 500, it should be appreciated that as few as one valve 500 may beused.

To activate the gripping apparatus 104, fluid flows through the one ormore feed lines 508. The fluid enters each of the actuation lines 506,then flows past the valves 500. The valves 500 operate in a manner thatallows fluid to flow toward the cylinder 502, but not back toward thefeed line 508. As the fluid continues to flow past the valves 500, itfills up each of the lines downstream of the valves 500. The fluid maythen begin to exert a force on the pistons 504. The force on the pistons504 causes the pistons 504 to move the slip ring 404 (shown in FIG. 4)and actuate the gripping apparatus 104. The slips 208 will then engagethe tubular 112. With the slips 208 fully engaged, the fluid will nolonger move the pistons 504 down. Introduction of fluid may be stoppedat a predetermined pressure, which may be monitored by the controller312 or an operator. The only force on the pistons 504 in the actuatedposition is the fluid pressure above the pistons 504. The system willremain in this state until the pressure is released by switches 510 orthe valves 500 or in the event of system failure. Each of the valves 500acts as a safety system to ensure that the gripping apparatus 104 doesnot inadvertently release the tubular 112. In operation, the slips 208may be released by actuating the switches 510 and allowing fluid toleave the top side of the pistons 504. Fluid is then introduced intorelease lines 512 in order to pressurize the bottom side of the pistons504. With the fluid released above the piston 504, there is noadditional force required to release the slips 208 other than frictionbetween the slips 208 and tubular 112. Although the valves 500 are shownin conjunction with the piston and cylinder assemblies 400, it should beappreciated that the valves 500 and hydraulic scheme may be used inconjunction with any actuator disclosed herein.

In yet another alternative embodiment, one or all of the piston andcylinder assemblies 400 may be equipped with an accumulator 514,optional, shown in FIG. 5. The accumulator 514 provides an additionalsafety feature to ensure that the gripping apparatus 104 does notrelease the tubular 112 prematurely. The accumulator 514, as shown, isbetween the valve 500 and the cylinder 502, within each of the actuationlines 506. An accumulator line 516 fluidly couples the accumulator 514to the actuation lines 506. Each accumulator 514 may include an internalbladder or diaphragm (not shown). The bladder is an impermeable elasticmembrane that separates the piston and cylinder assemblies 400 systemfluid from the compressible fluid in the accumulator 514. Beforeoperating the piston and cylinder assemblies 400 system fluid, theaccumulator 514 is filled with compressible fluid to a predeterminedpressure. With the compressible fluid pressure only in the accumulator514, the bladder will expand to cover the lower end towards theaccumulator line 516 of the accumulator 514. With the bladder in thatposition, the accumulator bladder has reached maximum expansion. Whenthe fluid for operating the piston and cylinder assemblies 400 entersthe accumulators 514, the membrane of the bladder begins to move uprelative to the accumulator lines 516. The bladder compresses thecompressible fluid further as the bladder moves up in the accumulators514. With the slips 208 fully engaged, the fluid will no longer move thepistons 504 down. The system fluid will continue to cause the bladder tocontract while compressing the compressible fluid in the accumulators514. Introduction of system fluid will be stopped at a predeterminedpressure. As discussed above, the system may remain in this state untilthe pressure is released by switches 510 or in the event of systemfailure.

In the event that the hydraulic system leaks, the system will slowlybegin to lose its system fluid. However, the compressible fluid in theaccumulators 514 maintains the pressure of the system fluid by addingvolume as the system fluid is lost. As the compressible fluid expands,the bladder expands, thus maintaining the pressure of the system fluidby adding volume to the system. The expansion of the bladder is relativeto the amount of system fluid lost. In other words, the pressure of thesystem fluid and in turn the pressure on the piston 504 remains constantas the system fluid is lost due to the expansion of the bladder. Thebladder continues to move as the system fluid leaks out until thebladder is fully expanded. Once the bladder has fully expanded, anyfurther leaking of the system fluid will cause a loss of pressure in thesystem. The pressure in the accumulators 514 may be monitored by thecontroller 312. Thus, upon loss of pressure in the accumulators 514, thecontroller 312 or an operator may increase the pressure in the pistonand cylinder assemblies 400 thereby preventing inadvertently releasingthe gripping apparatus 104. Each of the valves 500 and accumulators 514act independently for each of the piston and cylinder assemblies 400.Therefore, there may be one primary piston having a valve 500 and anaccumulator 514 and any number of redundant pistons having a valve 500and an accumulator 514, thereby providing an increased factor of safety.The accumulators 514 may be used with any actuator described herein.

In an alternative embodiment to the swivel 200 discussed above, a swivel600 couples directly to the actuator 106, as shown in FIG. 6A. Thisreduces the overall length of the gripping apparatus 104 by notrequiring the sub 215. The swivel 600 has a fluid nozzle 602 whichattaches to a control line 604 coupled to a fluid or electrical source606 (shown schematically). The swivel 600 additionally has a fluidchamber 180 which is in communication with the actuator 106 via a port608, for releasing or engaging the slips 208. The swivel 600 contains ahousing 610, which may comprise the fluid nozzle 602, two or more sealrings 612, and a base 614, which is connected directly to the rotatingmember. Further, the swivel 600 includes slip rings 616, which couplethe housing 610 to the base 614 while allowing the housing 610 to remainstationary while the base 614 rotates. FIG. 6B shows the swivel 600coupled to an actuator 106A according to an alternative embodiment. FIG.6C shows two swivels 600 attached to an actuator 106B. The actuator 106Bhas a piston 618 which moves up by fluid introduced from the lowerswivel 600 and moves down by fluid introduced from the upper swivel 600.The piston 618 operates the gripping apparatus 104. It should beappreciated that the swivels 600 may be used with any actuator 106arrangement disclosed herein or known in the art. Further, any number ofswivels 600 may be used.

In yet another alternative embodiment, the redundancy for any of theactuators described above may be achieved by a primary fluid system withan electrically powered backup. Further the primary system may beelectrically powered and the redundant system may be fluid operated.

In yet another alternative embodiment, the swivel 200 and/or 600described above may be in the form of a rotating union 620, as shown inFIG. 6D. The rotating union 620 includes an inner rotational member 622and an outer stationary member 624. The inner rotational member 622 maybe coupled to the rotating components of the tubular handling system102, such as the drive mechanism 108 and the actuator 106. The outerstationary member 624 is adapted to couple to one or more control linesfor operating the tubular handling system 102 components. As shown therotating union 620 includes two hydraulic fluid inlets 626 and fourpneumatic fluid inlets 628; however, it should be appreciated anycombination of pneumatic fluid, hydraulic fluid, electric, and fiberoptic inlet may be used, including only one hydraulic fluid inlet 626and/or one pneumatic fluid inlet 628. The inlets 626 and 628 mayoptionally include a valve for controlling flow. A bearing 630 may beincluded between the inner rotational member 622 and the outerstationary member 624 in order to bear radial and axial forces betweenthe two members. As shown the bearing 630 is located at each end of theouter stationary member 624.

The hydraulic fluid inlet 626 fluidly couples to an annular chamber 632via a port 634 through the outer stationary member 624. The annularchamber 632 encompasses the entire inner diameter of the outerstationary member 624. The annular chamber 632 fluidly couples to acontrol port 636 located within the inner rotational member 622. Thecontrol port 636 may be fluidly coupled to any of the components of thetubular handling system 102. For example, the control port 636 may becoupled to the actuator 106 in order to operate the primary actuatorand/or the redundant actuator.

In order to prevent leaking between the inner rotational member 622 andthe outer stationary member 624, a hydrodynamic seal 638 may be providedat a location in a recess 640 on each side of the annular chamber 632.As shown, the hydrodynamic seal 638 is a high speed lubrication finadapted to seal the increased pressures needed for the hydraulic fluid.The hydrodynamic seal 638 may be made of any material including but notlimited to rubber, a polymer, an elastomer. The hydrodynamic seal 638has an irregular shape and/or position in the recess 640. The irregularshape and/or position of the hydrodynamic seal 638 in the recess 640 isadapted to create a cavity 641 or space between the walls of the recess640 and the hydrodynamic seal 638. In operation, hydraulic fluid entersthe annular chamber 632 and continues into the cavities 641 between thehydrodynamic seal 638 and the recess 640. The hydraulic fluid moves inthe cavities as the inner rotational member 622 is rotated. Thismovement circulates the hydraulic fluid within the cavities 641 anddrives the hydraulic fluid between the hydrodynamic seal contactsurfaces. The circulation and driving of the hydraulic fluid creates alayer of hydraulic fluid between the surfaces of the hydrodynamic seal638, the recess 640 and the inner rotational member 622. The layer ofhydraulic fluid lubricates the hydrodynamic seal 638 in order to reduceheat generation and increase the life of the hydrodynamic seal. In analternative embodiment, the hydrodynamic seal 638 is narrower than therecess 640 while having a height which is substantially the same orgreater than the recess 640. The hydrodynamic seal 638 may also becircumferentially longer than the recess. This configuration forces thehydrodynamic seal 638 to bend and compress in the recess as shown in theform of the wavy hidden line on FIG. 6D. When rotated, the hydraulicfluid circulates in the cavities 641 as described above. Each of theinlets may include the hydrodynamic seal 638. Each of the inlets mayhave the control port 636 in order to operate separate tools of any ofthe components of the tubular handling system 102.

A seal 642 may be located between the inner rotational member 622 andthe outer stationary member 624 at a location in a recess 640 on eachside of the annular chamber 632 of the pneumatic fluid inlets 628. Theseal 642 may include a standard seal 644 on one side of the recess and alow friction pad 646. The low friction pad may comprise a low frictionpolymer including but not limited to Teflon™ and PEEK™. The low frictionpad 646 reduces the friction on the standard seal 644 during rotation.Any of the seals described herein may be used for any of the inlets 626and/or 628.

The tubular handling system 102 may include a compensator 700, as shownin FIG. 7. The compensator 700 compensates for the length loss due tothread make-up without having to lower the drive mechanism 108 and/ortop drive during the connection of the tubular 112 with the tubularstring 116. This system not only allows for length compensation as thethread is made up, it also controls the amount of weight applied to thethread being made up so that excessive weight is not applied to thethread during make up. The compensator 700, as shown, consists of one ormore compensating pistons 702 which are coupled on one end to a fixedlocation 704. The fixed location 704 may couple to any part of thetubular handling system 102 that is longitudinally fixed relative to thetubulars 112. The fixed location 704, as shown, is coupled to the topdrive. The other end of the compensating pistons 702 are operativelycoupled to the piston and cylinder assemblies 400 via a coupling ring706. The piston and cylinder assemblies 400 are coupled to the grippingapparatus 104 as described above. The compensating pistons 702 areadapted to remain stationary until a preset load is reached. Uponreaching the load, the compensator pistons will allow the coupling ring706 to move with the load, thereby allowing the gripping apparatus 104to move.

In operation, the gripping apparatus 104 grips the tubular 112. Withonly the tubular 112 coupled to the gripping apparatus 104, thecompensator piston 702 will remain in its original position. The tubular112 will then engage the tubular string 116, shown in FIG. 1. The drivemechanism 108 will then rotate the tubular 112 in order to couple thetubular 112 to the tubular string 116. As the threaded coupling is made,an additional load is applied to the gripping apparatus 104 and therebyto the compensating pistons 702. The compensator pistons 702 will movein response to the additional load thereby allowing the grippingapparatus 104 to move longitudinally down as the threaded connection iscompleted. Although the compensator 700 is shown with the piston andcylinder assemblies 400, it should be appreciated that the compensator700 may be used in conjunction with any actuator described herein.

The compensator pistons 702 may be controlled and monitored by thecontroller 312 via a control line(s) 708. The control line(s) 708enables the pressure in the compensating pistons 702 to be controlledand monitored in accordance with the operation being performed. Thecontroller 312 is capable of adjusting the sensitivity of thecompensator pistons 702 to enable the compensator pistons to move inresponse to different loads.

In another embodiment, the compensator 700 is simply a splined sleeve orcollar, not shown. The splined sleeve allows for longitudinal slip ormovement between the drive mechanism 108 and the gripping apparatus 104.In yet another embodiment, the compensator may include a combination ofpistons and the splined sleeve.

The actuator 106 may be adapted for interchangeable and/or modular use,as shown in FIGS. 8A-8E. That is, one actuator 106 may be adapted tooperate any size or variety of a modular gripping apparatus 804. FIG. 8Ashows the actuator 106 having the piston and cylinder assemblies 400,one or more compensator pistons 702, and an adapter 218 for coupling theactuator 106 to the drive mechanism 108 (shown in FIG. 1). The adapter218 may include a torque sub in order to monitor the torque applied tothe tubular 112. FIGS. 8B-8E show various exemplary modular grippingapparatus 804 that may be used with the actuator 106. Actuation of theselected gripping apparatus 804 is effected using a modular slip ring802. The modular slip ring 802, which is similar to slip ring 404described above, couples to the piston and cylinder assemblies 400 andis movable therewith, as described above. The modular slip ring 802 isadapted to couple to a mating slip ring 806 of the modular grippingapparatus 804. When coupled to the mating slip ring 806, the modularslip ring 802 may actuate the gripping apparatus 104 as described above.In this respect, the slip rings 802 and 806 move in unison in responseto actuation of the piston and cylinder assemblies 400, which, in turn,causes engagement or disengagement the gripping apparatus 104 from thetubular 112. Torque from the drive mechanism 108 may be transferred tothe modular gripping apparatus 804 using a universal couple 808. Asshow, the universal couple 808 is positioned at the end of a rotationalshaft 810 for each modular gripping apparatus 804. The universal couple808 is adapted to couple to a shaft within the actuator 106. With theuniversal couple 808 coupled to the shaft of the actuator 106, rotationmay be transferred from the drive mechanism 108 to the rotational shaft810 and in turn to the tubular via the modular gripping apparatus 804.

In operation, the modular aspect of the tubular handling system 102allows for quick and easy accommodation of any size tubular 112 withoutthe need for removing the actuator 106 and/or the drive mechanism 108.Thus, the external modular gripping apparatus 804, shown in FIG. 8B, maybe used initially to grip, couple, and drill with the tubular. Theexternal modular gripping apparatus 804 may then be removed byuncoupling the slip ring 806 from slip ring 802. The internal grippingapparatus 804, shown in FIG. 8E, may then be used to continue to couple,run, and drill with tubulars 112. It is contemplated that grippingapparatus of any suitable size may be used during operations. Further,any of the actuators 106 described herein may be used in conjunctionwith the modular gripping apparatus 804.

FIGS. 9A and 9B show a location system 900 that may be used with anytubular gripping assembly and any of the actuators 106 disclosed herein.The location system 900 may be incorporated into the actuator 106 havingthe piston and cylinder assembly 400, as shown. The location system 900is adapted to track the movement of the slip ring 404 or the piston rod406 as it is moved by the piston and cylinder assemblies 400. Thelocation system 900 may be in communication with the controller 312 inorder to monitor the engagement and disengagement of the grippingapparatus 104. The location system 900 tracks the position of pistonsthereby, tracking the position of the gripping apparatus 104. Thelocation system 900 may include a wheel 902 coupled to an arm 904, thatis coupled to the piston rod 406, or in the alternative, the sleeve 214,or the slip ring 404. As the piston rod 406 moves the slip ring 404 fromthe disengaged to the engaged position, the wheel rolls on a track 906.The track 906 may include a raised portion 907. As the wheel 902 reachesthe raised portion 907, it moves the arm 904 radially away from themandrel 212 of the gripping apparatus 104. The arm 904 is coupled to atrigger 908 which actuates a location indicator 910. Thus, as thetrigger 908 engages the location indicator 910, the height and positionof the trigger 908 inside the location indicator 910 indicates thelocation of the piston rods 406 and or the slip ring 404 and thus of thelocation of the slips 208, not shown. Although shown as the track 906having one raised portion it should be appreciated that the track 906may have any configuration and indicate the entire spectrum of locationsthe piston rod 406 and/or slip ring 404 may be during actuation anddisengagement of the gripping apparatus. The location system 900 maysend and/or receive a pneumatic and/or hydraulic signal to thecontroller 312 and/or fluid source and further may send an electronicsignal, either wirelessly or with a wired communication line. Further,the location system 900 may be any location locator including, but notlimited to, a hall effect, a strain gauge, or any other proximitysensor. The sensor communication signals may be sent back through theswivel and/or sent via radio frequency.

In yet another embodiment, the gripping apparatus 104 includes a sensor1000 for indicating that a stop collar 1002 of the gripping apparatus104 has reached the top of a tubular 112, as shown in FIGS. 10A and 10B.The stop collar 1002 is adapted to prevent the tubular 112 from movingbeyond the gripping apparatus 104 as the gripping apparatus 104 engagesthe tubular 112. The sensor 1000 may detect the tubular 112 when thetubular 112 is proximate the stop collar 1002. In use, the hoistingsystem 110 and/or the drive mechanism 108 will initially lower thegripping apparatus 104 toward the tubular 112 to urge the engagementportion of the gripping apparatus 104 to enter the tubular 112, orsurround the tubular 112 if the gripping apparatus is an externalgripper. As the hoisting system 110 and/or drive mechanism 108 continuesto move the gripping apparatus 104 relative to the tubular 112, thesensor 1000 will be actuated when the tubular 112 reaches apredetermined distance from the stop collar 1002. The sensor 1000 maysend a signal to the controller 312 or an operator in order to indicatethat the predetermined proximity of the stop collar 1002 to the tubular112 has been reached. The controller 312 and/or the operator may thenstop the hoisting system 110 and/or the drive mechanism 108 fromcontinuing the movement of the gripping apparatus 104 relative to thetubular 112. The gripping apparatus 104 may then be activated to gripthe tubular 112 to commence drilling and/or running operations.

The sensor 1000, as shown in FIGS. 10A and 10B, is a mechanical sensorwhich rests in a recess 1004 of the stop collar 1002 and is biased toproject below the bottom surface of the stop collar 1002. FIG. 10B showsthe sensor 1000 coupled to an activator 1006 which operates a controlvalve 1008. The activator 1006, as shown, is a rod which projectsthrough the stop collar 1002 and is coupled to the control valve 1008 onone end and to a contact 1010, which is adapted to engage the tubular112, on the other end. The sensor 1000 may include a spring 1007 forbiasing the activator 1006 toward the unengaged position. Thus, as thegripping apparatus 104 is lowered into the tubular 112, the contact 1010approaches the upper end of the tubular 112. Once the contact 1010engages the tubular 112, the control valve 1008 is actuated and sends asignal to the controller 312 or the operator indicating that thegripping apparatus 104 is in the tubular 112. Although shown as amechanical sensor, it should be appreciated that the sensor 1000 may beany sensor known in the art, such as a rod and piston assembly, a straingage, a proximity sensor, optical sensor, infrared, a laser sensor. Thesensor 1000 helps to prevent placing the full weight of the hoistingsystem 110, the actuator 106, and the drive mechanism 108 onto the topof the tubular 112 before the tubular 112 is connected to the tubularstring 116. In one embodiment, the sensor 1000 status may be sent backthrough the swivel and/or sent via radio frequency.

In yet another embodiment, the adapter 218, which may provide theconnection between the components of the tubular handling system 102,contains a lock 1100 as shown in FIG. 11. The adapter 218 is locatedbetween the drive mechanism 108 and the actuator 106; however, it shouldbe appreciated that the adapter 218 may be located between any of thetubular handling system 102 components. The lock 1100 prevents theinadvertent release of a connection between tubular handling system 102components as a result of rotation of the components. As shown, theconnection includes a pin connector 1102 of the drive mechanism 108adapted to couple to the box end 1103 of the actuator 106. Both the pinconnector 1102 and the box end 1103 have a shaped outer surface 1104.The shaped outer surface 1104 shown in FIG. 11A is an octagonalconfiguration; however, it should be appreciated that the shape may beany configuration capable of transferring torque, such as a gear orspline, a hex, a square, a locking key (pin), etc. The shaped outersurface 1104 is configured to match a shaped inner surface 1106 of thelock 1100. The lock 1100 may contain a set screw 1108 for coupling thelock 1100 to the pin connector 1102. Although the set screw 1108 isshown as connecting to the pin connector 1102, it should be appreciatedthat the set screw 1108 may couple to any part of the connection so longas the lock 1100 engages both the pin connector 1102 and the box end1103. Thus, in operation, the lock 1100 is placed on the pin connector1102 and the box end 1103 is coupled to the pin connector 1102. The lock1100 is then moved so that the shaped inner surface 1106 engages theshaped outer surface 1104 of both the pin connector 1102 and the box end1103. The set screws 1108 then couple the lock 1100 to the pin connector1102. The drive mechanism 108 may then be actuated to rotate the tubular112. As the drive mechanism 108 torques the connection, load istransferred through the lock 1100 in addition to the threadedconnection. The lock 1100 prevents the overloading or unthreading of theconnections. Although shown as the drive mechanism 108 having a pin endand the actuator 106 having a box end, any configuration may be used toensure connection. Further, the lock may contain a sprag clutch toengage a top drive quill, thus eliminating the requirement to modify theouter diameter of the top drive quill, not shown.

In yet another alternative embodiment, the adapter 218 is an externallocking tool 1110 as shown in FIGS. 11C and 11B. The external lockingtool 1110 may comprise two or more link elements 1112 connected toencompass the connection between tubular handling system 102 components.As shown, the link elements 1112 are pivotably connected to one anothervia a pin 1114. The pins 1114 may be removed in order to open theexternal locking tool 1110 and place the external locking tool 1110around the connection. The pin 1114 may then be reinstalled lock theexternal locking tool 1110 around the connection. Further, any number oflink elements 1112 may be removed or added in order to accommodate thesize of the connection. The link elements 1112, when connected, form aninterior diameter having two or more dies 1116. Each link element 1112may have one or more recess 1117 adapted to house the die 1116. Theinterior diameter is adapted to be equal to or larger than the outerdiameter of the connection between tubular handling system 102components. The dies 1116 have an engagement surface which is adapted togrippingly engage the outer diameter of the connection between thetubular handling system 102 components. In one embodiment, the dies 1116are large enough to traverse the connection between the tubular handlingsystem components. Optionally, the dies 1116 may be radially adjustablevia one or more adjustment screw 1120. The adjustment screw 1120 asshown traverses each of the link elements 1112. The adjustment screw1120 engages the die 1116 on the interior of the link element 1112 andis accessible for adjustment on the exterior of the link element 1112.Although the adjustment screw 1120 is shown as a screw, it should beappreciated that any method of moving the dies radially may be usedincluding but not limited to a fluid actuatable piston, an electricactuator, or a pin. In this manner, the link elements 1112 with the dies1116 may be coupled together around a connection between two components.The dies 1116 may then be adjusted, if necessary, via the adjustmentscrews 1120 in order to grippingly engage the connection. Each die 1116will transverse the connection and thereby grip both of the components.The dies 1116 coupled to the link elements 1112 will prevent thecomponents from rotating relative to one another, thereby preventinginadvertent release of the connection.

FIG. 11B shows an alternative embodiment of the external locking tool1110. As shown, each link element 1112 has at least two separate dies1116. The dies are independently adjustable via the adjustment screw1120. This allows each die 1116 to independently engage each componentof the connection. Therefore, the components may have varying outerdiameters and still be engaged by the separate dies 1116 of the externallocking tool 1110. With the dies 1116 grippingly engaged withcomponents, relative rotations between the components is prevented inthe same manner as described above.

In another embodiment, equipment 114 is a cementing plug launcher 1200adapted for use with the gripping apparatus 104, as shown in FIGS.12A-12B. The cementing plug launcher 1200 may be adapted to be engagedby any tubular handling system 102 described herein in addition to anydrilling rig tubular running device. For example, the cementing pluglauncher 1200 may be adapted to couple to an internal grippingapparatus, an external gripping apparatus, or any combination of anexternal and/or an internal gripping apparatus. Using the cementing pluglauncher 1200 in conjunction with the gripping apparatus 104 allows anoperator to use a cementing tool without the need to rig down thegripping apparatus 104 prior to use. This saves rig time and reduces theexposure of the tubular string 116 to the uncemented wellbore. Further,the cementing plug launcher 1200 may be brought to the rig floor as onecomplete assembly, which may be handled and coupled to the tubularstring 116 with the gripping apparatus. This allows fast operation whileprotecting the plugs inside the casing and the equipment 114. Further,the cementing plug launcher 1200 only needs to be attached to thetubular handling system 102 when the cementing operation is to takeplace. The cementing plug launcher 1200 may allow the tubular string 116to be cemented in place without the need to pump cement through thegripping apparatus 104, the actuator 106, and the drive mechanism 108.

The cementing plug launcher 1200 will be described as used with aninternal gripping apparatus 104. As shown in FIG. 12A, the launcher 1200has an upper joint 1202 and an optional launcher swivel 1204, a fluidinlet 1205, and a valve 1206. The swivel 1204 may function in the samemanner as the swivels mentioned above. The valve 1206 is shown as acheck valve; however, it may be any valve including, but not limited to,a ball valve, a gate valve, a one way valve, a relief valve, and a TIWvalve. The valve 1206 is adapted to prevent cement and/or drillingfluids from flowing through the cementing plug launcher 1200 during acementing operation. Further, the valve 1206 may prevent the pumpingpressure from affecting the load capacity of the gripping apparatus 104during circulation or cementing. The upper joint 1202 of the launcher1200 is adapted to be engaged by the gripping apparatus 104. Thus, afterthe tubular string 116 has been run and/or drilled or reamed to thedesired depth, the gripping apparatus 104 may release the tubular string116 and pick up the launcher 1200. To grip the launcher 1200, thegripping apparatus 104 is inserted into the upper joint 1202. Theactuator 106 then activates the slips 208 into gripping engagement withthe upper joint 1202. The gripping apparatus 104 and the cementing pluglauncher 1200 are then lifted by the hoisting system over the tubularstring 116. The hoisting system may then lower the cementing pluglauncher 1200 toward the tubular string 116 for engagement therewith.The drive mechanism 108 may then rotate the cementing plug launcher 1200to couple the cementing plug launcher 1200 to the tubular string 116.Thus, a cementing operation may be performed with little or nomodifications to the tubular handling system 102. In one embodiment, thetubular handling system 102 may have the sealing ability to allow fluidto be pumped into the inner diameter of the cementing plug launcher 1200above the valve 1206.

The cementing plug launcher 1200, shown in FIG. 12A, shows a typicallaunching head as is described in U.S. Pat. Nos. 5,787,979 and5,813,457, which are herein incorporated by reference in their entirety,and the additional features of the launcher swivel 1204 and the upperjoint 1202 adapted to be gripped by the gripping apparatus 104. Thelauncher 1200(a), shown in FIG. 12B, shows the use of a plug launchingsystem that uses conventional plugs as well as non-rotational plugs suchas described in U.S. Pat. No. 5,390,736, which is herein incorporated byreference in its entirety. The launcher 1200(a) further includes alauncher swivel 1204 that allows a fluid to be pumped into the wellwhile the valve 1206 prevents the fluid from flowing to the grippingapparatus 104. The fluid may be any fluid known in the art such ascement, production fluid, spacer fluid, mud, fluid to convert mud tocement, etc. The plug launching assembly 1200 and 1200A may allow thetubular string 116 to be rotated during the cementing operation. FIG.12C shows the cementing plug launcher 1200(b) adapted for remoteoperation as will be described below.

It should be appreciated that cementing plug launchers 1200 and 1200Amay be used in conjunction with clamps, casing elevators, or evenanother gripping apparatus such as a spear or external gripping deviceto connect to the previously run tubular string 116.

The cement plug launcher 1200 and 1200(A) are shown having manual plugreleases. In yet another alternative embodiment, the cement pluglauncher 1200 and 1200(A) are equipped with a remotely operatedactuation system. In this embodiment the manual plug releases arereplaced or equipped with by plug activators. The plug activators arefluid, electrically or wirelessly controlled from the controller 312.Therefore the controller or an operator at a remote location may releaseeach plug 1208 and 1210 at the desired time using the plug activators.The plug activators typically remove a member which prevents the plug1208/1210 from traveling down the cementing plug launcher 1200/1200(a)and into the tubular 112. Thus with the member removed after actuationof the plug activator, the plug 1208/1210 performs the cementingoperation. The fluid or electric lines used to operate the plugactivators may include a swivel in order to communicate with the plugactivators during rotation of the cementing plug launcher 1200 and1200(A). In an alternative, the plug activators may release a ball or adart adapted for use with the plugs 1208 and 1210.

During a cementing operation it may be beneficial to reciprocate and/orrotate the tubular string 116 as the cement enters the annulus betweenthe wellbore 115 and the tubular string 116. The movement, reciprocationand/or rotation, may be accomplished by the hoisting system 110 and thedrive mechanism 108 and helps ensure that the cement is distributed inthe annulus. The remotely operated actuation system for the cement pluglauncher may be beneficial during the movement of the tubular string 116in order to prevent operators from injury while releasing the plugs 1208and 1210 due to the movement of the cement plug launcher.

While the cementing plug launcher may be used or discussed with theredundant safety mechanism for a gripping apparatus, it will beunderstood that the launcher need not be associated with any otheraspect or subject matter included herein.

In an additional embodiment, the tubular handling system 102 may includea release 1300, shown in FIG. 13. During the operation of the tubularhandling system with a slip type internal gripping apparatus it ispossible that the slips 208, shown in FIG. 2, may become stuck in thetubular 112. This may occur when the slips 208 of the gripping apparatus104 inadvertently engage the tubular 112 at a position where thegripping apparatus 104 is unable to move relative to the tubular 112.For instance the stop collar 1002 of the gripping apparatus 104encounters the top of the tubular 112 and the slips 208 engage thetubular 112. At this point, pulling the gripping apparatus 104 uprelative to the tubular 112 further engages the slips 208 with thetubular 112, additionally movement downward relative to the tubular 112,to release the slips 208, is prohibited due to the stop collar 1002 andthe top of the tubular 112 being in contact with one another. Therelease 1300 is adapted to selectively release the gripping apparatus104 from the tubular 112 in the event that the gripping apparatus isstuck and may be incorporated into the stop collar 1002 or may be aseparate unit. The release 1300 may have a release piston 1302 and arelease chamber 1304. The release chamber 1304 may be coupled to therelease piston via a fluid resistor 1306, such as a LEE AXIAL VISCO JET™and a valve 1307. The valve 1307 as shown is a one way valve, or checkvalve. The fluid resistor 1306 prevents fluid pressure in the releasechamber 1304 from quickly actuating the release piston 1302. The valve1307 prevents fluid from flowing from the release chamber 1304 towardthe release piston 1302 while allowing fluid to flow in the oppositedirection. The release 1300 may further include a biasing member 1308adapted to biased the release piston 1302 toward the unengaged positionas shown in FIG. 13. The release 1300 operates when stop collar 1002engages the tubular 112 and weight is placed on the mandrel 212 of thegripping apparatus 104 by the hoisting system, shown in FIG. 1. Themandrel 212 may be coupled to the release piston 1302 by a couplingdevice 1309. A downward force placed on the mandrel 212 compresses thefluid in the release chamber 1304. The initial compression will not movethe release piston 1302 due to the fluid resistor 1306. Continuedcompression of the release chamber 1304 flows fluid slowly through thefluid resistor 1306 and acts on the release piston 1302. As the releasepiston 1302 actuates a piston cylinder 1310, the piston cylinder 1310moves the mandrel 212 up relative to the stop collar 1002. Thus, themandrel 212 slowly disengages the slips 208 from the tubular 112 withcontinued compression of the release chamber 1304. Further, the fluidresistor 1306 prevents accidental release of the slips 208 caused bysudden weight on the mandrel 212. The continued actuation of the releasechamber 1304 to the maximum piston stroke will release the slips 208.The gripping apparatus 104 may then be removed from the tubular. Whenweight is removed from the stop collar 1002 the pressure in the releasechamber quickly subsides. The biasing member 1308 pushes the piston backtoward the unengaged position and the valve 1307 allows the fluid toreturn to the release chamber. In another embodiment the release 1300 isequipped with an optional shoulder 1312. The shoulder 1312 is adapted torest on top of the tubular 112.

FIG. 14 is a schematic view of an integrated safety system 1400 and/oran interlock. The integrated safety system 1400 may be adapted toprevent damage to the tubular 112 and/or the tubular string 116 duringoperation of the tubular handling system 102. In one embodiment, theintegrated safety system 1400 is electronically controlled by thecontroller 312. The integrated safety system 1400 is adapted to preventthe release of the gripping apparatus 104 prior to the gripper 119gripping the tubular 112 and/or the tubular string 116. For example, ina tubular running operation, the controller 312 may initially activatethe actuator 106 of the gripping apparatus 104 to grip the tubular 112.The controller 312 may then activate rotation of the gripping apparatus104 to couple the tubular 112 to the tubular string 116. The controller312 may then release the gripper 119 while still gripping the tubular112 and the tubular string 116 with the gripping apparatus 104. Thecontroller 312 will prevent the release of the tubular 112 prior to thegripper 119 re-gripping the tubular 112 and the tubular string 116. Oncethe gripper 119 has re-gripped the tubular 112, the controller 312 willallow the release of the tubular 112 by the gripping apparatus 104.

The integrated safety system 1400 may also be capable of monitoring theproper amount of torque in the threads of the tubulars 112 during makeup. This ensures that the threads are not damaged during make up andthat the connection is secure. Examples of suitable safety systems areillustrated in U.S. Pat. No. 6,742,596 and U.S. Patent ApplicationPublication Nos. U.S. 2005/0096846, 2004/0173358, and 2004/0144547,which are herein incorporated by reference in their entirety.

In another embodiment, the integrated safety system 1400 may incorporatethe location system 900. The location system 900 sends a signal to thecontroller 312, which gives the status of the gripping apparatus 104 inrelation to the tubular 112. In other words, the location system 900indicates to the controller 312 when the tubular 112 is gripped orungripped by the gripping apparatus 104. In operation, after thegripping apparatus 104 grips the tubular 112, the location system 900sends a signal to the controller 312 indicating that the tubular 112 isgripped and it is safe to lift the gripping apparatus 104. The grippingapparatus 104 is manipulated by the drive mechanism 108 and/or thehoisting system 110 to couple the tubular 112 to the tubular string 116.The controller 312 may then open the gripper 119 to release the tubularstring 116. The tubular 112 is lowered and regripped by the gripper 119as described above. The controller 312 then releases the grippingapparatus 104 from the tubular 112. The location system 900 informs thecontroller 312 when the gripping apparatus 104 is safely disengaged fromthe tubular 112. The gripping apparatus 104 may then be removed from thetubular 112 without marking or damaging the tubular 112.

The integrated safety system 1400 may incorporate the sensor 1000 inanother embodiment. The sensor 1000 sends a signal to the controller 312when the stop collar 1002 is proximate to the tubular 112. Therefore, asthe gripping apparatus 104 approaches the tubular 112 and/or the tubularstring 116, a signal is sent to the controller 312 before the stopcollar 1002 hits the tubular 112. The controller 312 may then stop themovement of the gripping apparatus 104 and, in some instances, raise thegripping apparatus 104 depending on the operation. The stopping of thegripping apparatus prevents placing weight on the tubular 112 when do sois not desired. In another embodiment, the signal may set off a visualand/or audible alarm in order to allow an operator to make a decision onany necessary steps to take.

In yet another embodiment, the integrated safety system 1400 mayincorporate the release 1300. The release 1300 may send a signal to thecontroller 312 when the release begins to activate the slow release ofthe gripping apparatus 104. The controller 312 may then override therelease 1300, lift the gripping apparatus 104, and/or initiate theactuator 106 in order to override the release 1300, depending on thesituation. For example, if the slow release of the gripping apparatus104 is initiated by the release 1300 prior to the gripper 119 grippingthe tubular 112, the controller may override the release 1300, therebypreventing the gripping apparatus 104 from releasing the tubular 112.

In yet another alternative embodiment, the integrated safety system 1400is adapted to control the compensator 700 via the controller 312. Whenthe compensator 700 is initiated during the coupling of the tubular 112to the tubular string 116, the compensator 700 may send a signal to thecontroller 312. The compensator 700 may measure the distance the tubular112 has moved down during coupling. The distance traveled by thecompensator 700 would indicate whether the connection had been madebetween the tubular 112 and the tubular string 116. With the connectionmade, the controller 312 may now allow the gripping apparatus 104 todisengage the tubular 112 and/or the compensator to return to itsinitial position.

In an alternative embodiment, the integrated safety system may be one ormore mechanical locks which prevent the operation of individualcontrollers for one rig component before the engagement of another rigcomponent.

In operation, the gripping apparatus 104 attaches to the drive mechanism108 or the swivel 200, which are coupled to the hoisting system 110 ofthe rig 100. The tubular 112 is engaged by an elevator (not shown). Theelevator may be any elevator known in the art and may be coupled to thetubular handling system 102 by any suitable method known in the art. Theelevator then brings the tubular 112 proximate the gripping apparatus104. In an alternative embodiment, the gripping apparatus may be broughtto the tubular 112. The gripping apparatus 104 is then lowered by thehoisting system 110 or the elevator raises the tubular 112 relative tothe gripping apparatus 104 until the slips 208 are inside the tubular112. When the stop collar 1002 of the gripping apparatus 104 gets closeto the tubular 112, the sensor 1000 may send a signal to the controller312. The controller 312 may then stop the relative movement between thegripping apparatus 104 and the tubular 112.

With the gripping apparatus 104 at the desired location, the controller312 either automatically or at the command of an operator activates theactuator 106. At least the primary actuator of the actuator 106 isactivated to urge the slips 208 into engagement with the tubular 112.One or more redundant actuators may be actuated either simultaneouslywith or after the primary actuator is actuated. The primary actuatorwill ensure that the slips 208 engage the tubular while the redundantactuators will ensure that the tubular 112 is not prematurely releasedby the gripping apparatus 104. The operation of the primary actuator andthe redundant actuators are monitored by the controller 312 and/or theoperator.

As the actuator 106 activates the gripping apparatus 104, the locationsystem 900 may send a signal to the controller 312 regarding thelocation of the slips 208 in relation to the tubular 112. After thetubular 112 is engaged, the drive mechanism 108 and or hoisting system110 may bear the weight of the tubular 112 for connection to a tubularstring 116. The tubular handling system 102 then lowers the tubular 112until the tubular 112 is engaged with the tubular string 116. The drivemechanism 108 may then rotate the tubular 112 in order to couple thetubular 112 to the tubular string 116. During the coupling of thetubular 112 to the tubular string 116, the compensators 700 maycompensate for any axial movement of the tubular 112 relative to thedrive mechanism 108. The compensation prevents damage to the tubular 112threads. The compensator 700 may indicate to the controller 312 theextent of the connection between the tubular 112 and the tubular string116. As the drive mechanism 108 transfers rotation to the tubular 112via the gripping apparatus 104 and the slips 208, the swivel allows forcommunication between the rotating components and the controller 312 orany fluid/electric sources. After the connection of the tubular 112 tothe tubular string 116 is made up, the gripper 119 may release thetubular string 116, while the gripping apparatus 104 continues tosupport the weight of the tubular 112 and the tubular string 116. Thehoisting system 110 then lowers the tubular string 116 to the desiredlocation. The gripper 119 then grips the tubular string 116. Thecontroller 312 may then disengage the slips 208 either by use of therelease 1300 or de-activating the actuator 106 to release the tubularstring 116. During this sequence, the integrated safety system 1400 mayprevent the tubular string 116 from being inadvertently dropped into thewellbore 115. The process may then be repeated until the tubular string116 is at a desired length.

As the tubular string 116 is lowered into the wellbore 115, drillingfluids may be pumped into the tubular string 116 through the grippingapparatus 104. The drilling fluids flow through the flow path 206 (shownin FIG. 2) of the gripping apparatus 104. The packer 204 of the pack off202 prevents the drilling fluids from inadvertently escaping from thetop of the tubular string 116.

After the lowering the tubular 112 and the tubular string 116, thegripping apparatus 104 may then be used to engage the equipment 114 inthe manner described above. In one embodiment, the equipment is thecement plug launcher 1200/1200A shown in FIGS. 12A-12B. The grippingapparatus 104 first engages the upper joint 1202, then the cement pluglauncher 1200 couples to the tubular string 116. Thereafter, a firstplug 1208 is dropped into the tubular string 116, either by thecontroller 312 or manually by an operator. Cement may then be pumpedinto the cement plug launcher 1200 via the fluid inlet 1205 and flowdown the tubular string 116 behind the first plug 1208. The swivel 1204allows the cement to be pumped into the cement plug launcher 1200 whilethe drive mechanism 108 rotates and/or reciprocating the tubular string116, if necessary. After the necessary volume of cement has been pumpedinto the tubular string 116, the controller 312 and/or operator drops asecond plug 1210. The second plug 1210 may be pushed down the tubularstring 116 by any suitable fluid such as drilling fluid. The second plug1210 continues to move down the tubular string 116 until it lands on thefirst plug 1208. The cement is then allowed to dry in an annulus betweenthe tubular string 116 and the wellbore 115. The cement plug launcher1200 may then be removed from the tubular string 116 and thereafterdisconnected from the gripping apparatus 104.

With the tubular string 116 cemented in place, the gripping apparatus104 may be removed from the actuator 106. One of the modular grippingapparatus 804, shown in FIG. 8, may then be coupled to the actuator 106in order to accommodate a different sized tubular 112. A new tubularstring 116 may be made up and run into the cemented tubular string 116in the same manner as described above. The new tubular string may beequipped with a milling and/or drilling tool at its lower end in orderto mill out any debris in the tubular string 116 and/or drill thewellbore 115. The same procedure as described above is used to run andset this tubular string 116 into the wellbore. This process may berepeated until the tubular running is completed. This process may bereversed in order to remove tubulars from the wellbore 115.

In yet another embodiment described herein, an apparatus for gripping atubular for use with a top drive is disclosed. The apparatus includes aconnection at one end for rotationally fixing the apparatus relative tothe top drive and one or more gripping members at a second end forgripping the tubular. Further, the apparatus includes a primary actuatorconfigured to move and hold the gripping members in contact with thetubular, and a backup assembly adapted to maintain the gripping memberin contact with the tubular.

In yet another embodiment, the primary actuator is fluidly operated.

In yet another embodiment, the primary actuator is electricallyoperated.

In yet another embodiment, the backup assembly comprises a selectivelypowered redundant actuator.

In yet another embodiment, the backup assembly is hydraulicallyoperated.

In yet another embodiment, a monitor is coupled to a controller formonitoring a condition in the backup assembly.

In yet another embodiment, the monitor monitors a condition in theprimary actuator.

In yet another embodiment, the backup assembly comprises a check valveoperable in conjunction with the primary actuator to ensure the primaryactuator remains operable in the event of hydraulic failure.

In yet another embodiment, the backup assembly further includes anadditional source of fluids to ensure the primary actuator remainsoperable in the event of hydraulic failure.

In yet another embodiment, a first swivel in configured tocommunicatively couple the primary actuator to a fluid source.Additionally a second swivel may couple to the backup assemblyconfigured to communicatively couple the backup assembly to the fluidsource. Additionally, a second fluid source may be provided.

In yet another embodiment, the connection comprises a lock forpreventing the apparatus and the top drive from rotating independentlyof one another. Further, the lock may include a shaped sleeve forengaging a shaped outer diameter of the top drive and the apparatus.Alternatively, the lock may include two or more link elements configuredto surround the connection, and one or more gripping dies on an insidesurface of each link element, the one or more gripping dies configuredto engage the apparatus and the top drive.

In yet another embodiment, a release may be actuated by applying weightto the apparatus to actuate a fluid operated piston. Further, the fluidoperated piston may be coupled to a fluid resistor for constrictingfluid flow. Additionally, the fluid resistor may act to release thegripping members from the tubular using a substantially constant forceapplied over time.

In yet another embodiment described herein, an apparatus for gripping atubular for use in a wellbore is described. The apparatus may include agripping member for gripping the tubular, wherein the gripping member iscoupled to a rotating mandrel. Further, the apparatus may include anactuator for actuating the gripping member and a locking member forlocking the gripping member into engagement with an inner diameter ofthe tubular. Additionally, the apparatus may include a swivel forconnecting the actuator to the gripping member.

In yet another embodiment, the actuator comprises one or more chamberscontrolled by fluid pressure. Further, the fluid pressure may actuate apiston.

In yet another embodiment, the locking member includes one or morepressure chambers connected to a fluid source.

In yet another embodiment, the locking member is one or more checkvalves provided between a fluid source and the one or more pressurechambers.

In yet another embodiment, a controller for monitoring the fluidpressure in the one or more pressure chambers in provided.

In yet another embodiment, a release actuated by applying weight to thegripping apparatus to actuate a fluid operated piston is included.Further, the fluid operated piston may be coupled to a fluid resistorfor constricting fluid flow. Additionally the fluid resistor may act torelease the gripping members using a constant force applied over time.

In yet another embodiment described herein, an apparatus for gripping atubular for use in a wellbore is described. The apparatus may include aset of slips connectable to a rotating mandrel for engaging an innerdiameter of the tubular. Further, the apparatus may include a pluralityof fluid chambers for actuating the slips and a swivel for fluidlyconnecting a fluid source to the plurality of fluid chambers.

In yet another embodiment, the chambers comprise one or more primaryactuators and one or more redundant actuators.

In yet another embodiment, the redundant actuator has a locking member.

In yet another embodiment, the locking member comprises a check valveconfigured to hold pressure in the redundant actuator. Further, thecheck valve may allow one way flow of fluid into at least one of theplurality of fluid chambers.

In yet another embodiment, the fluid source supplies a hydraulic fluid.

In yet another embodiment, the fluid source comprises a pneumatic fluid.

In yet another embodiment, a controller for monitoring at least one ofthe plurality of fluid chambers is provided.

In yet another embodiment, a sensor may be coupled to a stop collar,wherein the sensor is configured to communicate to the controller whenthe stop collar engages the tubular.

In yet another embodiment, a control line may be connectable to theswivel and the plurality of fluid chambers.

In yet another embodiment described herein, a method for connecting atubular is described. The method includes providing a fluid pressurefrom a fluid source and conveying the fluid pressure through a swivel toa plurality of chambers. Further, the swivel may have two or moreannular seals located in a recess on each side of a fluid inlet. Themethod additionally includes actuating a gripping member to grip thetubular, wherein the gripping member is actuated by applying a fluidpressure to a piston within the plurality of chambers. The methodadditionally may include rotating the tubular using the gripping memberand moving a pressurized fluid into cavities between the two or moreannular seals and the recess in response to rotating the tubular.Further, the method may include continuing to supply the fluid sourcethrough the swivel and into the chambers via the swivel during rotation.

In yet another embodiment, the method further includes locking at leastone chamber of the plurality of chambers upon actuation, wherein lockingthe at least one chamber may include flowing fluid through a checkvalve.

In yet another embodiment, the method further includes monitoring atleast one of the plurality of chambers with a controller. Additionally,the gripping member may be operatively coupled to a top drive. Further,the gripping member may be rotated by the top drive.

In yet another embodiment described herein, a tubular handling system isdescribed. The tubular handling system includes a tubular torque devicecoupled to a hoisting system and a gripping apparatus. Additionally, thetubular handling system includes a cementing plug launcher configured toselectively coupled to the gripping apparatus having a tubular housingfor receiving the gripping member, and one or more plugs located withinthe tubular housing configured to perform a cementing operation.

In yet another embodiment, a check valve may be disposed within thetubular housing configured to prevent fluid flow from the launcher tothe gripping apparatus.

In yet another embodiment, a swivel that allows for a fluid to be pumpedinto the launcher while the torque device rotates the launcher isprovided.

In yet another embodiment, the gripping member comprises a spear.

In yet another embodiment, the gripping member comprises an externaltubular gripper.

In yet another embodiment described herein, a method of completing awellbore is described. The method includes providing a tubular handlingsystem coupled to a hoisting system, wherein the tubular handling systemcomprises a gripping apparatus, an actuator, and a torquing apparatus.The method further includes gripping a first tubular using the grippingapparatus and coupling the first tubular to a tubular string by rotatingthe first tubular using the torquing apparatus, wherein the tubularstring is partially located within the wellbore. Additionally, themethod may include lowering the first tubular and the tubular string andreleasing the first tubular from the gripping apparatus. The method mayfurther include gripping a cementing tool using the gripping apparatusand coupling the cementing tool to the first tubular by rotating thecementing tool. Additionally the method may include flowing cement intothe cementing tool and cementing at least a portion of the tubularstring into the wellbore.

In yet another embodiment, the method includes preventing cement fromflowing into contact with the gripping apparatus with a check valve.

In yet another embodiment described herein, a release for releasing agripping apparatus from a tubular is described. The release includes apiston and a piston cylinder operatively coupled to a mandrel of thegripping apparatus. The release further includes a fluid resistorconfigured to fluidly couple a release chamber to the piston byproviding a constrained fluid path. Additionally the release may includea shoulder adapted to engage a tubular and increase pressure in therelease chamber as weight is applied to the shoulder, and whereincontinued weight on the shoulder slowly actuates the piston therebyslowly releasing the gripping apparatus from the tubular.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

What is claimed is:
 1. A method of handling a tubular, comprising:gripping the tubular with a gripping apparatus; sending an electronicsignal to a controller indicating that the gripping apparatus isgripping the tubular; and controlling actuation of the grippingapparatus using the controller to prevent inadvertent release of thetubular.
 2. The method of claim 1, further comprising coupling thetubular to a tubular string that is supported by a spider apparatus, andcontrolling actuation of the spider apparatus using the controller toprevent inadvertent release of the tubular string.
 3. The method ofclaim 2, further comprising: releasing the tubular string from thespider apparatus while supporting the tubular and tubular string withthe gripping apparatus; lowering the tubular and tubular string throughthe spider apparatus; gripping the tubular with the spider apparatus;and using the controller to prevent the gripping apparatus fromreleasing the tubular prior to supporting both the tubular and tubularstring with the spider apparatus.
 4. The method of claim 3, furthercomprising actuating the spider apparatus using the controller tothereby grip the tubular.
 5. The method of claim 4, further comprisingsending an electronic signal to the controller indicating that thespider apparatus is gripping the tubular, and then actuating thegripping apparatus using the controller to thereby release the tubular.6. The method of claim 1, further comprising monitoring a position ofthe gripping apparatus relative to the tubular, and sending anelectronic signal to the controller indicating the position of thegripping apparatus.
 7. The method of claim 6, wherein monitoring theposition of the gripping apparatus comprises tracking a position of aslip ring or a piston rod of a piston assembly operable to actuate thegripping apparatus.
 8. The method of claim 6, wherein monitoring theposition of the gripping apparatus comprises monitoring a distance ofthe gripping apparatus relative to the tubular.
 9. The method of claim1, further comprising measuring an amount of pressure or temperature ina piston assembly operable to actuate the gripping apparatus, andsending an electronic signal to the controller indicating the amount ofpressure or temperature.
 10. The method of claim 2, further comprisingactuating a top drive to rotate the gripping apparatus and the tubularand thereby couple the tubular to the tubular string to form a tubularconnection.
 11. The method of claim 1, further comprising actuating ahoisting assembly using the controller to thereby raise or lower thegripping apparatus.
 12. A tubular handling system, comprising: agripping apparatus; and a controller operable to receive an electronicsignal indicating a position of the gripping apparatus, wherein thecontroller is operable to control actuation of the gripping apparatus toprevent inadvertent release of a tubular supported by the grippingapparatus.
 13. The system of claim 12, further comprising a spiderapparatus, wherein the controller is operable to control actuation ofthe spider apparatus to prevent inadvertent release of a tubular stringsupported by the spider apparatus.
 14. The system of claim 13, furthercomprising a sensor operable to monitor a position of the spiderapparatus, and operable to send an electronic signal to the controllerindicating the position of the spider apparatus.
 15. The system of claim12, further comprising a sensor operable to monitor the position of oneor more engagement members of the gripping apparatus, and operable tosend the electronic signal to the controller indicating the position ofthe one or more engagement members.
 16. A method of handling a tubular,comprising: gripping the tubular with a gripping apparatus; sending anelectronic signal to a controller indicating that the gripping apparatusis gripping the tubular; actuating a top drive using the controller torotate the gripping apparatus and the tubular; and actuating thegripping apparatus using the controller to prevent inadvertent releaseof the tubular.
 17. The method of claim 16, further comprisingmonitoring a position of the gripping apparatus relative to the tubular,and sending an electronic signal to the controller indicating theposition of the gripping apparatus.
 18. The method of claim 17, whereinmonitoring the position of the gripping apparatus comprises tracking aposition of a slip ring or a piston rod of a piston assembly operable toactuate the gripping apparatus.
 19. A tubular handling system,comprising: a gripping apparatus; a controller operable to receive anelectronic signal indicating a position of the gripping apparatus,wherein the controller is operable to actuate the gripping apparatus toprevent inadvertent release of a tubular supported by the grippingapparatus; and a top drive, wherein the controller is operable toactuate the top drive to rotate the gripping apparatus.
 20. The systemof claim 19, further comprising a sensor operable to monitor an amountof torque supplied by the top drive, and operable to send an electronicsignal to the controller indicating the amount of torque supplied by thetop drive.